Expressing our internal states and understanding those of others

Significance Vitality form is a term that describes the manner with which actions are performed. Despite their crucial importance in interpersonal communication, vitality forms have been almost completely neglected in neuroscience. Here, using a functional MRI technique, we investigated the neural correlates of vitality forms in three tasks: action observation, imagination, and execution. We found that, in all three tasks, there is a common specific activation of the dorsocentral sector of the insula in addition to the parietofrontal network that is typically active during arm movements production and observation. Thus, the dorsocentral part of the insula seems to represent a fundamental and previously unsuspected node that modulates the cortical motor circuits, allowing individuals to express their vitality forms and understand those of others. Vitality form is a term that describes the style with which motor actions are performed (e.g., rude, gentle, etc.). They represent one characterizing element of conscious and unconscious bodily communication. Despite their importance in interpersonal behavior, vitality forms have been, until now, virtually neglected in neuroscience. Here, using the functional MRI (fMRI) technique, we investigated the neural correlates of vitality forms in three different tasks: action observation, imagination, and execution. Conjunction analysis showed that, in all three tasks, there is a common, consistent activation of the dorsocentral sector of the insula. In addition, a common activation of the parietofrontal network, typically active during arm movements production, planning, and observation, was also found. We conclude that the dorsocentral part of the insula is a key element of the system that modulates the cortical motor activity, allowing individuals to express their internal states through action vitality forms. Recent monkey anatomical data show that the dorsocentral sector of the insula is, indeed, connected with the cortical circuit involved in the control of arm movements.